This is a very nice doughnut flavor with extra sweetness. This flavor does contain a trace amount of Acetoin (custard note)
Frosted Donut Flavoring Concentrate (TFA) by The Flavor Apprentice Learn More

Koolada (menthyl methyl lactate) is used specifically to give that "cold" feeling at the back of the mouth. It does not really have a 'taste', but it can be used in conjunction with menthol.
Try using 1 drop per 1ml of eliquid.
Flavoring for Electronic Cigarette e-Liquid Learn More